Patricia Stallings: Wrongful Murder Conviction Overturned by Science

Patricia Stallings’ wrongful conviction was a 1991 Missouri murder case in which flawed laboratory testing led a jury to convict a mother of poisoning her infant son with antifreeze. The substance in Ryan Stallings’ blood was not ethylene glycol at all. It was propionic acid, a toxic compound that builds up in children with methylmalonic acidemia, a rare inherited metabolic disease. After independent scientists retested the blood using more precise methods, prosecutors dropped the charges and Patricia was released after roughly thirteen months in prison.

How Ryan Stallings Died

Ryan was born in April 1989. On July 9, at about three months old, he was brought to Cardinal Glennon Hospital in St. Louis with lethargy, vomiting, and rapid breathing.¹ Two separate diagnostic laboratories reported extremely high levels of ethylene glycol, the main ingredient in antifreeze, in his blood.² Doctors treated him for antifreeze poisoning with an ethanol drip, the standard antidote.

After Ryan was discharged, relatives took custody under a safety plan. On September 1, during a supervised visit with his mother, he fell ill again. He was rehospitalized and died on September 7, 1989.² Patricia was arrested and charged with first-degree murder the next day.³

The Case Against Patricia

Jefferson County Prosecutor George B. McElroy III built the case on three pieces of evidence: the lab results showing ethylene glycol in Ryan’s blood, traces of the substance allegedly found on a baby bottle, and a jug of antifreeze in the Stallings home at Lake Wauwanoka.³ The autopsy also noted calcium oxalate crystals in Ryan’s brain, presented as further evidence of poisoning.²

McElroy told the jury not to try to understand why Patricia had poisoned her child, only that the evidence showed she had done it.²

Why the Defense Failed

Patricia’s attorney, Eric Rathbone, took the case as a favor to the family because no other lawyer would. He held a degree in biochemistry and intended to argue that Ryan had died of a metabolic disorder.⁴ He never built the record to support it.

Rathbone subpoenaed no expert witnesses. He did not depose the prosecution’s medical experts. He said he had consulted a specialist who told him MMA byproducts could not be mistaken for ethylene glycol, and he relied on his own scientific background to conclude the lab findings were sound. He never contacted Dr. James Shoemaker of St. Louis University, who had already tested a saved sample of Ryan’s blood and found results consistent with MMA; Rathbone assumed Shoemaker would only confirm poisoning.⁴

When Rathbone tried to raise the metabolic disorder theory at trial without supporting evidence, Circuit Judge Gary P. Kramer refused to allow it, telling him, “You have to prepare and subpoena the evidence necessary to prove your theory!”⁴ On February 1, 1991, the jury convicted Patricia of first-degree murder. Judge Kramer sentenced her to life in prison without the possibility of parole.²

The Second Son Who Changed Everything

While Patricia was awaiting trial, she gave birth to a second son, David Jr., in February 1990. He was immediately placed in protective custody with no contact with his mother.³ He soon developed the same symptoms his brother had. Doctors at St. Louis Children’s Hospital diagnosed him with methylmalonic acidemia, a rare hereditary metabolic disease.²

MMA is caused by a deficiency in a protein called cobalamin adenosyltransferase, which prevents the body from properly metabolizing certain amino acids. A child with the disease cannot have caught it from a mother in custody; he could only have inherited it. That fact never reached Ryan’s jury.

How the Science Was Corrected

After Patricia’s case aired on Unsolved Mysteries in May 1991, doctors around the country contacted the program to say Ryan’s symptoms matched MMA.⁵ St. Louis attorney Robert Ritter visited Patricia at the Renz Correctional Center for Women and took on the case.⁶

Ritter brought in Dr. William Sly, chairman of the Department of Biochemistry at St. Louis University, and Dr. James Shoemaker, who ran a metabolic testing lab at the same institution. Shoemaker had already found high levels of propionic acid in a saved sample of Ryan’s blood. Using gas chromatography paired with mass spectrometry, a more precise method than the standard gas chromatography the original labs had used, he confirmed the substance was propionic acid and not ethylene glycol.¹ The original laboratories had identified substances by retention time alone, meaning anything appearing in a certain analytical window was labeled ethylene glycol without further confirmation.² Propionic acid has a retention time nearly indistinguishable from ethylene glycol.⁷

To satisfy the prosecutor’s demand for an independent national expert, Ritter brought in Dr. Piero Rinaldo, a Yale geneticist who specialized in inherited metabolic diseases. Rinaldo called the labs’ methodology “totally unacceptable” and said, “I was astonished. I couldn’t believe that somebody would let this go through a criminal trial unchallenged.”² He tested the baby bottle prosecutors had cited and found no ethylene glycol.⁴ He also concluded that the calcium oxalate crystals in Ryan’s brain were a byproduct of the ethanol drip doctors had administered to treat the poisoning they mistakenly diagnosed. In his assessment, that ethanol treatment was “completely inappropriate for someone with MMA” and likely hastened Ryan’s death.

Charges Dismissed and an Apology

After reviewing the expert findings, McElroy acknowledged that Rathbone’s defense had been “woefully inadequate” and filed a motion for a new trial on the grounds of ineffective counsel. Judge Kramer granted it, saying it was the first time he had known a prosecutor to make such an acknowledgment.⁴ Ritter secured the new trial on July 29, 1991.⁶

Rather than retry the case, McElroy moved to dismiss it. “My charge as a prosecutor is to seek justice,” he said, “and justice for Patricia Stallings required that I seek a dismissal.”⁴ On September 19, 1991, the Jefferson County Circuit Court dismissed all charges. Patricia had spent roughly thirteen months in prison.² David Jr. was returned to his parents. At a press conference in Ritter’s office, the prosecutor issued a formal apology on behalf of the state of Missouri.⁶ Ritter filed to correct Ryan’s death certificate and used Missouri’s criminal record expungement act to clear Patricia’s record.

Settlements

In 1993, the Stallings family received out-of-court settlements for Ryan’s wrongful death from Cardinal Glennon Children’s Hospital and the diagnostic laboratories whose flawed testing had driven the prosecution. The amounts were not publicly disclosed.²

1
GWU Himmelfarb Health Sciences Library. Disorder in the Court: Methylmalonic Acidemia
2
National Center for Biotechnology Information. Genetic Twists of Fate – The Stallings Case
3
Northwestern Pritzker School of Law. Patricia Stallings Exoneration
4
Justice Denied. Patricia Stallings Case
5
Unsolved Mysteries. Patty Stallings
6
Super Lawyers. The Right Man for the Job
7
ScienceDirect. Misidentification of Propionic Acid as Ethylene Glycol